Many modern industrial, commercial, aerospace, military and medical systems depend on reliable valves for fluid handling. The trends in fluid handling systems are toward smaller, more distributed and more portable systems for increasing uses in instrumentation and control. For example, microfluidic devices have become popular in such applications as analytical testing. In many cases, microfluidic devices are constructed in a multi-layer, often laminated, structure where each layer has channels and structures fabricated from a laminate material to form microscale voids or channels where fluids flow. The control and pumping of fluids through these channels is often affected by either external pressurized fluid forced into the laminate, or by structures located within the microfluidic device.
Many different types of valves for use in controlling fluids in such microscale devices have been developed. Many of these valves, however, are on-off type valves, and do not allow for the fluid flow to be modulated. What would be desirable, therefore, is a microfluidic modulating valve that can selectively modulate the size of a flow channel to allow for the fluid flow to be selectively modulated.